Tympanoplasty is a surgical operation performed for the reconstruction of the ear drum, also known as the tympanic membrane. The most common indication for tympanoplasty are tympanic membrane perforations. The tympanic membrane can become perforated through a number of ways, including middle ear infections, external auditory canal infections, blunt trauma and iatrogenic causes. Although some tympanic membrane perforations can heal on their own, often surgery is necessary to repair the damage. Typically, a large tympanic membrane perforation is treated by inserting a graft into the ear adjacent the perforation. Various graft materials have been used for tympanoplasty, including fascia, perichondrium, vein tissue, dura, skin and cartilage.
Cartilage grafts have become popular due to cartilage being more rigid and resistive to absorption, having good long-term survival and being nourished largely by diffusion. In a typical cartilage tympanoplasty procedure, cartilage is harvested from the patient's ear, such as from the tragus, the cymba choncae or the choncal bowel. Then various techniques can be employed by the surgeon to manually shape the cartilage graft prior to implantation. The standard implantation procedure for larger perforations is known as medial grafting and involves placing the graft material beneath or medial to the original tympanic membrane. Small perforations can often be repaired by inserting a graft directly into the perforation.
Various products are available for thinning cartilage to an appropriate thickness (typically between 0.3 mm and 0.5 mm) for implantation. However, the final shape of the graft is manually determined by the surgeon. This “eyeballing” technique of shaping the graft is time consuming and can result in an imprecisely shaped graft that will not properly anchor adjacent the tympanic membrane. As such, it would be desirable for a device to provide simple and accurate shaping of cartilage grafts for tympanoplasty.